ICAR: endoscopic skull‐base surgery

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Inclusive quarkonium production at forward rapidity in pp collisions at root s=8 TeV

We report on the inclusive production cross sections of J/psi, psi(2S), gamma(1S), gamma(2S) and gamma(3S), measured at forward rapidity with the ALICE detector in pp collisions at a center-of-mass energy root s = 8 TeV. The analysis is based on data collected at the LHC and corresponds to an integrated luminosity of 1.23 pb(-1). Quarkonia are reconstructed in the dimuon-decay channel. The differential production cross sections are measured as a function of the transverse momentum p(T) and rapidity y, over the p(T) ranges 0 < p(T) < 20 GeV/c for J/psi, 0 < p(T) < 12 GeV/c for all other resonances, and for 2.5 < y < 4. The cross sections, integrated over p(T) and y, and assuming unpolarized quarkonia, are sigma(J/psi) = 8.98 +/- 0.04 +/- 0.82 mu b, sigma(psi(2S)) = 1.23 +/- 0.08 +/- 0.22 mu b, sigma(gamma(1S)) = 71 +/- 6 +/- 7 nb, sigma(gamma(2S)) = 26 +/- 5 +/- 4 nb and sigma(gamma(3S)) = 9 +/- 4 +/- 1 nb, where the first uncertainty is statistical and the second one is systematic. These values agree, within at most 1.4 sigma, with measurements performed by the LHCb collaboration in the same rapidity range

Measurement of D-s(+) product ion and nuclear modification factor in Pb-Pb collisions at root S-NN=2.76 TeV

The production of prompt D-s(+) mesons was measured for the first time in collisions of heavy nuclei with the ALICE detector at the LHC. The analysis was performed on a data sample of Pb-Pb collisions at a centre-of-mass energy per nucleon pair, root s(NN), of 2.76 TeV in two different centrality classes, namely 0-10% and 20-50%. D-s(+) mesons and their antiparticles were reconstructed at mid-rapidity from their hadronic decay channel D-s(+) -> phi pi(+), with phi -> K-K+, in the transverse momentum intervals 4 < p(T) < 12 GeV/c and 6 < p(T) < 12 GeV/c for the 0-10% and 20-50% centrality classes, respectively. The nuclear modi fication factor R-AA was computed by comparing the p(T)-differential production yields in Pb-Pb collisions to those in proton-proton (pp) collisions at the same energy. This pp reference was obtained using the cross section measured at root s = 7 TeV and scaled to root s = 2.76TeV. The R-AA of D-s(+) mesons was compared to that of non-strange D mesons in the 10% most central Pb-Pb collisions. At high p(T) (8 < p(T) < 12 GeV/c) a suppression of the D-s(+)-meson yield by a factor of about three, compatible within uncertainties with that of non-strange D mesons, is observed. At lower p(T) (4 < p(T) < 8 GeV/c) the values of the D-s(+)-meson R-AA are larger than those of non-strange D mesons, although compatible within uncertainties. The production ratios D-s(+)/D-0 and D-s(+)/D+ were also measured in Pb-Pb collisions and compared to their values in proton-proton collisions

Charged-particle multiplicities in proton-proton collisions at root s=0.9 to 8 TeV

A detailed study of pseudorapidity densities and multiplicity distributions of primary charged particles produced in proton-proton collisions, atv root s = 0.9, 2.36, 2.76, 7 and 8 TeV, in the pseudorapidity range vertical bar n vertical bar< 2, was carried out using the ALICE detector. Measurements were obtained for three event classes: inelastic, non-single diffractive and events with at least one charged particle in the pseudorapidity interval vertical bar n vertical bar<1. The use of an improved track-counting algorithm combined with ALICE's measurements of diffractive processes allows a higher precision compared to our previous publications. A KNO scaling study was performed in the pseudorapidity intervals vertical bar n vertical bar< 0.5, 1.0 and 1.5. The data are compared to other experimental results and to models as implemented in Monte Carlo event generators PHOJET and recent tunes of PYTHIA6, PYTHIA8 and EPOS

Transverse momentum dependence of D-meson production in Pb-Pb collisions at root S-NN=2.76 TeV

The production of prompt charmed mesons D-0, D+ and D*(+), and their antiparticles, was measured with the ALICE detector in Pb-Pb collisions at the centre-of-mass energy per nucleon pair, root s(NN), of 2.76 TeV. The production yields for rapidity vertical bar y vertical bar < 0.5 are presented as a function of transverse momentum, p(T), in the interval 1-36 GeV/c for the centrality class 0-10% and in the interval 1-16 GeV/c for the centrality class 30-50%. The nuclear modification factor R-AA was computed using a proton-proton reference at root s = 2.76 TeV, based on measurements at root s = 7 TeV and on theoretical calculations. A maximum suppression by a factor of 5-6 with respect to binary-scaled pp yields is observed for the most central collisions at p(T) of about 10 GeV/c. A suppression by a factor of about 2-3 persists at the highest p(T) covered by the measurements. At low p(T) (1-3 GeV/c), the R-AA has large uncertainties that span the range 0.35 (factor of about 3 suppression) to 1 (no suppression). In all p(T) intervals, the R-AA is larger in the 30-50% centrality class compared to central collisions. The D-meson R-AA is also compared with that of charged pions and, at large p(T), charged hadrons, and with model calculations